Bunka Knife – Retro Series 8.3″ in Tricolour Damascus Steel
Care Instructions for Tricolour Copper Damascus Kitchen Knives
Natural Oxidation:
Copper may darken or change colour when exposed to air — this is a natural process and does not affect performance or safety.
Cleaning and Maintenance:
To restore shine, periodically wipe the blade with lemon juice, rinse, and dry thoroughly. The citric acid helps remove oxidation and renew the polished surface.
Avoid Moisture:
Minimise contact with water; always clean and dry immediately after use.
Blade Composition
The blade features a 12Cr18MoV stainless steel core, enriched with molybdenum and vanadium for enhanced hardness (60 ±2 HRC) and long-lasting edge retention. Surrounding the core are alternating layers of 316L stainless steel, brass, and purple copper — together forming a 37-layer tricolour Damascus pattern.
The 316L layers contribute high corrosion resistance and define the bright steel tones. The brass layers add ductility and a warm golden contrast, while the purple copper layers bring softness and develop a deep violet hue over time, enhancing the three-dimensional visual depth of the blade.
All 37 layers are hot-forged under a controlled atmosphere, achieving perfect metallurgical bonding. After forging, the billet undergoes normalisation to relieve internal stresses, followed by vacuum hardening with cryogenic treatment (–75 °C) to convert retained austenite into martensite — increasing hardness without brittleness. Finally, tempering at 180–200 °C balances toughness and wear resistance.
A final acid etching step reveals the authentic tricolour Damascus pattern, highlighting the contrast between steel, brass, and copper.
| Feature |
Details |
| Blade Length |
8.3 inches (approx. 210 mm) |
| Shape |
Bunka (wide blade with gently curved, pointed tip) |
| Core Material |
12Cr18MoV stainless steel (with Mo & V for hardness and edge retention) |
| Outer Layers |
37 total layers: 1 core + 18 alternating layers of 316L stainless steel, brass, and purple copper on each side |
| 316L Stainless Steel |
Superior corrosion resistance; provides bright contrast |
| Brass |
High ductility; adds golden warmth to the Damascus pattern |
| Purple Copper |
Soft, develops deep purple tones, enhancing 3D appearance |
| Heat Treatment |
Vacuum hardening → cryogenic process (–75 °C) → tempering (180–200 °C) |
| Core Hardness |
60 ± 2 HRC |
| Edge Angle |
15° ± 1 per side |
| Surface Finish |
Fine grinding, mirror polishing, and acid etching to reveal Damascus layers |
| Handle Material |
Figured sycamore wood with padauk burl accents |
| Handle Fixing |
Brass mosaic rivets |
| Approx. Weight |
~200 g (may vary with wood grain pattern) |
| Key Features |
Precision cutting, corrosion resistance, unique tricolour pattern, artistic design |
| Packaging |
Premium handmade gift box |
| Standard |
Entity |
Description |
| CE Standard |
CE |
Ensures compliance with EU health, safety, and environmental protection requirements. |
| EEC Certification |
EEC |
Confirms conformity with European material and process standards. |
| LFGB (Germany) |
LFGB |
Guarantees that all food-contact materials meet German food safety legislation. |
